When it comes to mulch, certain types have the potential to be more combustible than others and additional factors can contribute to this risk. Residentslocatedin or around our Wildland Urban Interface (WUI) should learn about the best possible mulch types to use and where it should be placed around your home. Here are a few considerations:
- Dyed or colored mulch: Mulch that has been dyed or treated with artificial colors may contain flammable additives or chemicals.
- Fine textured or shredded mulch: Sometimes referred to as ‘Gorilla Hair’ mulch which consists of fine particles or shredded materials can be more prone to rapid ignition. These mulches contributed to fire spread and damage during the 2017 fires and the most recent Glass Fire in 2020.
- Dry or improperly maintained mulch: Mulch that is excessively dry can easily ignite and spread fire.
- Mulch made of Rubber: Mulch made of rubber material should be avoided. During ignition testing, rubber mulch has shown to produce significant flame height and heat.
- Accumulation of debris: If mulch is surrounded by accumulated dry leaves, twigs, or other combustible materials, it adds to the risk and combustibility of ground mulch in place.
Within0-5 ftof the house and other structures:
Maintaining a noncombustible, ignition–resistant area immediately adjacent to the house and other structures is particularly important. Within five feet of the home, use noncombustible rock, gravel, concrete, and pavers. During a wildfire, embers may accumulate in this area, providing an ample source of ignition for combustible materials. While some mulch ground covers are less hazardous than others, they are all considered combustible materials. Mulch types that have a smoldering combustion risk may not be readily noticeable during a wildfire event and may go undetected by firefighters.
Within 5ft – 30 ft feet of the house and other structures:
Mulches fall into two main categories, organic and inorganic. Organic mulches usually consist of pine needles, wheat straw, pine bark nuggets, shredded cedar and redwood bark, and other recycled wood chips. Inorganic mulch consists of non-plant material such as rock, gravel, and brick chips, which can be categorized as hardscape. Hardscape can also consist of rocks, stones, bricks, and concrete pathways. The main benefit of mulch is that it keeps the soil temperature cool and moist, which in the long run conserves water. Hardscape material increases the temperature making your soil, plants, and trees hotter than normal which, in turn, requires more water to keep them healthy. Using the appropriate mulch is key and planning out locations of plants or garden beds that will need the mulch is equally important. We recommend at least 30’ of clearance from your homeif they are in use. Compost or large bark chips are usually the best option for fire resistance.To learn more visitSRCity.org/WildfireReady
FAQs
During a wildfire, embers may accumulate in this area, providing an ample source of ignition for combustible materials. While some mulch ground covers are less hazardous than others, they are all considered combustible materials.
What is the most fire resistant mulch? ›
Inorganic mulches such as decomposed granite, gravel, or rocks offer superior fire-proofing as landscape mulches and should be used when mulch is needed within five feet of buildings or any combustible structural materials such as siding or decking.
How do you fire proof mulch? ›
Drip irrigation & mulching: Use drip irrigation for efficient watering and choose non-combustible mulch like rock to prevent fire hazards near your home. Avoid combustible mulches: Combustible mulches near the home create an additional fire risk (Quarles & Smith, 2008).
Can a large pile of mulch catch on fire? ›
Large piles of mulch can spontaneously combust from the heat they generate. It is important to be vigilant and employ good housekeeping. The distance between mulch piles keeps a fire from spreading from one pile to another, or to a building.
What is the danger of mulch? ›
Mulch is a combustible material that can be easily ignited by improperly discarded smoking materials. Hundreds of small and large fires are started this way every year. The risk is that what starts as a small outdoor mulch fire can quickly spread to buildings.
What is the best ground cover for fire protection? ›
Use rock, composted or heavy bark mulch in flower beds and gardens as ground cover for bare spaces to act as effective firebreaks.
How to prevent mulch fires? ›
Regular watering that keeps mulch consistently moist helps to prevent ignition. Avoid placing mulch near decorative lights or other electric devices. If you notice a mulch fire, extinguish the fire and then report the fire to 911 immediately.
What mulch to avoid? ›
Finally, avoid large, bark type mulch or big wood chips. Since these big pieces take a long time to decompose, and they end up depriving the soil and plants of nutrients.
What is the best mulch to use near the house? ›
But, generally, using organic mulch made from wood chips or bark will be the best choice. It's one of the easiest and least expensive ways to ensure the long-term health and fertility of your soil and the health of your trees and shrubs.
How do you fireproof a house from a wildfire? ›
Cover exterior attic vents and under-eave vents with metal wire mesh no larger than 1/8 inch to keep embers out. Install a fire block in the gap between the top of framed walls and the foundation of the house to starve the fire of oxygen and prevent it from spreading.
Rock Mulch
Rock, gravel, pebbles and other stones can be applied to landscaping features such as flowerbeds to suppress weed growth and retain moisture. Rock is economical and seldom needs replacement. It also complements modern architectural features and more minimalist landscaping.
How to fireproof the outside of your home? ›
Outside the home
Consider using concrete, stone, brick or fireproof tiling for your outside deck rather than wood. Instead of wood chips or straw, add stone or gravel around your garden or landscaping. Maintain your lawn, keeping bushes and trees trimmed to discourage dry brush fires.
How to care for mulch so it doesn't combust? ›
Keeping plants and mulch consistently moist with regular and proper watering can discourage mulch fire problems. Ensuring your irrigation system is working correctly and that you're watering at adequate intervals can do this for you.
Which mulch is most flammable? ›
Shredded Rubber, Pine Needles and Shredded Cedar Bark have among the highest hazardous combustion characteristics and are recommended for use only in areas more than 30 feet from the house. Although shredded rubber is not a natural woody mulch, it is still flammable and will smolder and flame.
How do you extinguish a mulch fire? ›
The best practice to extinguish mulch/compost fires is to isolate the burning material by removing the surrounding uninvolved material, spread out the burning material and then apply water to only that material.
Are wood chips on the ground a fire hazard? ›
Contrary to popular belief, using wood chips in your garden does not pose a fire hazard. This is because wood chips need to be moist to decompose, and keeping them moist also prevents any fire from occurring.
Is it OK to put mulch around a fire pit? ›
The answer is YES, but you make sure that the mulch is at least six inches away from the edge of the fire pit. This will help to prevent the mulch from catching on fire.
Is it OK to burn mulch? ›
Never burn old organic mulch! If bagging up old mulch isn't your idea of a fun afternoon, you can call a professional landscaping company to dispose of your old mulch.
